This invention relates to space-time coding and, more particularly, it relates to space-time coding and transmission in an environment that has no knowledge of the transmission channel parameters.
Hocwald and Marzetta, in “Unitary space-time modulation for multiple-antenna communications in Rayleigh flat fading,” IEEE Trans. Inform. Theory, March 2000, proposed unitary space-time codes with interesting codes, but they have exponential encoding and decoding complexity. Subsequently, they came up with a second construction that has polynomial encoding but exponential decoding complexity, which makes their use formidable in practical situations. In the aforementioned Ser. No. 09/296,514 patent application, we proposed a coding scheme based on orthogonal designs, it being the first scheme that provides simple encoding/decoding algorithms. Thereafter, Hughes introduced a construction based on group codes that also has simple encoding/decoding algorithms, and Hocwald, et al. presented a construction with polynomial encoding but with a suboptimal decoding algorithm.
This disclosure is provided because the parent application discloses an arrangement where two transmitting antennas are employed and at least to some artisans questioned whether the arrangement can be expanded to more than two antennas.